Centrifugal type engine governor having hydraulically assisted speed setting control



March 1-7, 1953 R, R. ROBINSON x-:TAL 2,631,837

CENTRIFUGAL TYPE ENGINE GOVERNOR HAVING HYDRAULICALLY Filed NOV. 7, 1951ASSISTED SPEED SETTING CONTROL 2 SHEETS-SHEET 1 mwa-2.9

ATTRIVEY March 17, 1953 R. R. ROBINSON ET AL 2,63,837

CENTRTFUGAL- TYPE ENGINE GovERNoN HAVING HYDRAULICALLY AssIsTED SPEEDSETTING CONTROL Filed Nov. 7, 1951 2 SHEETS- SHEET 2 n'. il

IN VEN TORS.

ATTRNEY.'

Patented Mar. 17, 1953 CENTRIFUGAL TYPE ENGINE GOVERNOR HAVINGHYDRAULICALLY ASSISTED SPEED SETTING CONTROL- Ronald R. Robinson,Morton, and Kenneth J. assignors to Caterpillar Tractor Co., Peoria,Ill., a corporation of Illi- Fleck, Peoria, Ill.,

nois

Application November 7, 1951, seria1No.255,2s2

4 Claims.

The present invention relates to engine governors in general and moreparticularly to a centrifugal type governor with a hydraulic boosterbetween the control member and governor spring for reacting the force ofthe governor spring and which may be readily converted from ahydraulically boosted governor to a mechanically operated governor witha minimum of changes in the parts.

In most engines of the compression ignition type a spring-balancedcentrifugal governor is provided for controlling the quantity of fuelmetered to the engine in response to engine load. In governors of thistype the governed speed of the engine is established by the load imposedon the governor spring through either manual or pedal actuated linkageassociated with the governor spring. Manually actuated linkages usuallyinclude a locking device such as a ratchet for reacting the force of thegovernor and are commonly employed on stationary engines, tractors, andlike installations in which it is not necessary to make frequent changesin the governed speed of the engine. However, in automotive typevehicles in which frequent changes in the governed Vspeed of the engineare encountered it is desirable to employ pedal actuated linkage forloading the governor spring. In the past, one of the principaldifliculties encountered in this type of governor is that the pedal issubject to variable forces exerted by the governor ily weights undervarying operating conditions, and it is impractical for an operator tomaintain any established governor setting by the pressure of his foot onthe pedal.

AIt is an object of the present invention to provide a spring-balancedcentrifugal governor for an internal combustion engine having hydraulicmeans for loading the governor spring wherein the forces of the governorspring and yweights will react against the hydraulic means instead ofthe control linkage. It is another object of this invention to provide aspring-balanced centrifugal governor for an internal combustion enginehaving a hydraulic booster for loading the governor spring in whichstops are provided limiting relative movement of the hydraulic boosterparts to permit mechanical operation of the governor in the absence ofhydraulic pressure. ,Another object of this invention is the provisionof a spring-balanced centrifugal governor for an internal combustionengine having a mechanical connection between the governor springloading control and the engine fuel metering control to provide apositive connection between the two when' the' governor is moved to itsshut-down position. Still another object of this invention is theprovision of a spring-balanced governor for an internal combustionengine which may be readily converted to either mechanically actuated orhydraulically actuated with a minimum of changes to the governor parts.,

Other objects and advantages of this invention will be made apparent inthe following specification wherein reference is made to theaccompanying drawings.

In the drawings:

Fig. 1 is a vertical sectional view through a hydraulically boostedengine governor embodying the present invention;

Fig. 2 is a sectional view taken along the line II-II of Fig. 1;

Fig. 3 is a sectional view taken along the line III-III of Fig. 1; and

Fig. 4 is a view like Fig. l of a modified form of this invention.

In Fig. l of the drawings, the invention is illustrated in itsassociation with a fuel pump housing part of which is shown at I0. Thehousing contains a plurality of fuel pumps (not shown) one for eachcylinder of the engine, of a well-known type in which angular adjustmentof the pump plungers determines the quantity of fuel delivered to therespective cylinders upon each stroke of the plunger. Angular adjustmentof the fuel pump plungers is accomplished by a rack bar meshing with agear on each plunger and is controlled by the position of the flyweightsforming a part of the governor.

The governor is illustrated as comprising a housing II secured as by capscrews I2 to the fuel pump housing I0 and enclosing a pair ofcentrifugally actuated ilyweights I3 supported for rocking movementabout pins I4 carried in outwardly extending ears I5 formed on a shaftI. The shaft I6 is journalled for rotation in spaced bearings Il and I8carried in the fuel pump housing I and a cover I9 secured to thegovernor housing by cap screws 20 (Fig. 2) respectively. The end ofshaft I6 extending into the fuel pump housing carries a gear 22 adaptedto mesh with other gearing (not shown) to drive the shaft in timedrelation to the engine crankshaft.

The yweights are provided with inwardly extending fingers 23 whichsupport rollers 24 adapted to engage a thrust washer 26 passed on to theend of a sleeve 21 slidably and rotatably mounted on the shaft I6.Washer 26 is adapted to engage the inner race of a thru-st bearing 28,the outer race of which is carried in a collar 29 carried for slidingmovement on sleeve 2l. The

periphery of sliding collar 29 is provided with groove 3| for thereception of pins 32 carried in arms 33 extending from and forming apart of a yoke 34, the ends of which are journalled for rocking movementin the housing II. The yoke 34 is provided with a lever 35 extendingthrough a slotted opening v36 in the fuel pump housing II) and itsextending end is adapted to be connected to the fuel pump rack bar (notshown) to effect adjustment of the quantity of fuel metered tothe enginein response to movement of the fly weights.

Outward swinging of the iiyweights I3 by centrifugal action moving theyoke 314 in a direction to decrease the quantity of fuel metered to theengine is opposed by a governor spring 3'8 interposed between slidingcollar 29 and a piston 39 carried for limited sliding movement in asleeve 4I. The sleeve 4I embraces a hollow cylindrical projecting part42 of cover I9 ari-d is adapted for axial sliding movement thereonforming an extensible cylinder adapted to receive fluid under pressurefrom the engine lubricating oil pump (not shown) through a pipe 43 and apassage y44 in cover I9. An oil seal 45 is provided `between sleeve 4Iand the exterior of cylindrical part 412 so that the oil entering thecylinder i-s discharged into the governor housing through notches 46provided in the periphery of the open end of sleeve 4I. The piston isprovided with an outwardly extending flange 41 which cooperates with thenotches I44S to control the rate of fluid discharge from the interior ofthe cylinder. By controlling the rate of uid discharged from thecylinder the pressure acting on the piston 39 may be varied .to increaseo-r decrease the load on the governor spring 38 it .being understoodthat a constant flow .of oil under pressure from the pipe 43 passesthrough the cylinder and escapes lthrough the notches 46.

Movement of sleeve 4I to vary the uid. pressure acting on piston 39 isaccomplished through a forked control lever 4B having ends 49 and 50 ofreduced diameter supported for rocking movement in covers I secured asby cap screws 52 to the sides of the governor housing I I. The extendingparts of the lever 48 carry pins 54 which are received in a groove 55provided on the eX- terior of sleeve 4I. The end 50 of control lever 48extends through cover 5I and carries a lever 56 forming a part of thepedal actuated control linkage (not shown). Provision is made foractuating the piston mechanically in the absence of hydraulic pressureo-r in the event that 'it is desirable to move the control more rapidlythan can be accomplished by uid pressure by means of a pair of snaprings 51 and 58 carried in grooves formed in the interior of sleeve 4I.One of the snap rings is disposed on each side of the iiange 41 on thepiston and they are adapted to engage opposite sides of the flangeactuating the piston upon movement of the sleeve 4I. The snap rings arespaced from each other to allow sufficient relative movementlbetween thepiston and sleeve to control the oil flow through the notches 46 undernormal conditions of operation.

The maximum governor spring load and therefore the maximum governedspeed of the engine is limited by an adjustable screw 6I threadedythrough the housing II and adapted to engage a stop member 62 securedas by cap screws 63 to control lever 48. The high idle adjusting screwis retained in its position of adjustment by the reception of its headin a recess 64 pro-vided in a cover 65 secured as by a cap screw 66(Fig. 3)

to the governor housing. The lo-W speed or idle position of the controllever is established by engagement of a spring-loaded plunger 61 carriedin stop member 62 with a pin 68 carried in a pair of spaced links 6'9pivotally supported from the 'control lever 48. The pin 68 is alsocarried in a recess 1I formed in a block 112 having a threadedengagement with Va low speed adjusting screw 13 extending through an-dadapted for rotation in suitable openings in the housing II. The lowspeed adjusting screw lis held .against axial movement by a head 114 anda snap ring 15 carried in a groove in the screw. The low speed adjustingscrew is held against rotation by the reception of its head in a recess116 provided in the cover 65. Engagement of the spring-loaded plunger 61with pin 68 establishes the position of the control lever at the lowestidling speed of the engine. However, when it is desired to shut theengine down lthe control lever 48 may be rocked upwardly as viewed inFig. 3 to shut oil the supply of fuel to the engine depressing theplunger 61 to permit it to pass over the pin 68. After the plunger 61passes beyond the pin 68 it will :again be extended by the spring andprevent the accidental return of the governor control to an operatingposition.

Movement of the control lever 4B to the shutoff position also actuatesyoke 34 moving the lfuel pump rack bar to its fuel shut-off position.Thi-s is accomplished by a link 11 connecting control lever 4B to yoke34. The link 11 is provided with an elongated slot 18 illustrated inFig. 2 for the reception of a pin 19 extending from one of the arms 33o-f yoke 34 so .that during normal operation of the governor the yoke isfree to move in response to the unbalance of forces between theilyweights and governor spring to vary the quantity of fue-l metered tothe engine in response to engine load. However, when the control lever4-8 is moved to the shut-off position the end of slot 18 engages pin 19rocking yoke 34 in a direction to shut off the supply of fuel to theengine.

The governor also includes means for controlling the torquecharacteristics of the engine comprising an arm 83 formed on the yoke 34which at its extending end carries a set screw 84 adapted to engage aspring 85. The spring 85 is spaced from a solid stop 816 by a spacingblock 81 and all three are secured as by cap screws 86 to a boss 89forming a part of the governor housing II. Engagement of the set screw8f4 with .the spring 815 establishes the position of the yoke 34 andfuel pump rack bar at `full load rated speed of the engine. Upondecreasing speed of the engine due to overload, the spring 65 yields tothe .force of the governor spring permitting further movement of theyoke 34 in the direction to increase the quantity of fuel metered to theengine until the spring 85 engages the solid stop 86 to produce acorresponding increase in engine torque. The position of the yoke 3.4controlling the quantity of `fuel metered to the engine at full load maybe adjusted by manipulation of set screw 84 which is retained in itsposition of adjustment by a lock nut 96. v

In Fig. 4, a modified form of this invention is illustrated in whichlike parts are identified with the same reference characters primed. Theprincipal difference in this modification is that the hydraulic boosterfor loading the governor spring is replaced by a direct mechanicalconnection with the control lever 48. In this modification the cover I9illustrated in Figs. 1 and 2 is replaced by a cover 9| having acylindrical projecting part 92 which is embraced by sliding collar 93adapted for axial sliding movement thereon. The sliding collar 93 servesas a retainer for one end of the governor spring 38 and is provided witha groove 94 in its periphery for the reception of pins 54 carried in theextending arms of control lever 48'. With the construction shown in thismodification, adjustment of the speed of the engine is accomplished inexactly the same manner except that the force or load on the governorspring must be reacted by a suitable friction or throttle locking device(not shown). This modification is particularly adapted for use onstationary engines, tractors, or the like which are not subject tofrequent variations in the governed speed of the engine.

We claim:

1. In a spring balanced centrifugal type engine governor control meanscomprising an open ended cylinder adapted to receive fluid underpressure, a sleeve surrounding and slidable over the open end of thecylinder to vary its effective length, a seat for the governor springcarried for sliding movement within the sleeve, said sleeve havingexhaust openings adapted to be uncovered by relative movement betweenthe spring seat and sleeve to vary the pressure exerted on the governorspring by the uid in the cylinder.

2. In a spring balanced centrifugal type engine governor control meanscomprising an open ended cylinder adapted to receive iiuid underpressure, a sleeve surrounding and slidable over the open end of thecylinder to vary its effective length, a seat for the governor springcarried for sliding movement within the sleeve, said sleeve havingexhaust openings adapted to be uncovered by relative movement betweenthe spring seat and sleeve to vary the pressure exerted on the governorspring by the uid in the cylinder, and stop means on the sleeve adaptedto engage the spring seat limiting relative movement between the sleeveand spring seat, said stop means being effective to actuate the springseat in the absence of fluid pressure in the cylinder.

3. In a spring balanced centrifugal type 4engine governor havingcentrifugally actuated iiy- Weights for positioning a fuel controlmember, a governor spring opposing the action of the ilyweights, andcontrol means comprising an open ended cylinder adapted to receive fluidunder pressure, a sleeve surrounding and slidable over the open end ofthe cylinder to vary its effective length, a seat for the governorspring carried for sliding movement within the sleeve, said sleevehaving' exhaust openings adapted to be uncovered by relative movementbetween the spring seat and sleeve to vary the pressure exerted on thegovernor spring by the fluid in the cylinder, means for positioning thesleeve on said cylinder, and a link connecting said means forpositioning the sleeve with the fuel control member and having a slottedconnection therewith to prevent interference with movement of the fuelcontrol member except upon movement of the sleeve positioning means tothe engine shutoff position.

4. In a spring balanced centrifugal type engine governor havingcentrifugally actuated flyweights for positioning a fuel control member,a governor spring opposing the action of the flyweights, and a movableseat for the governor spring, control means for varying the position ofthe seat to vary the load on the governor spring, link means connectingthe control means with the fuel control member, a slidable connectionbetween the fuel control member and the link to permit unrestrainedmovement of the fuel control member throughout its entire range exceptwhen the control means is moved to the engine shut-01T position.

RONALD R. ROBINSON. KENNETH J. FLECK.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 2,165,817 Saiord July 11, 1939FOREIGN PATENTS Number Country Date 192,287 Switzerland Oct. 16, 1937

